| /* |
| * linux/fs/fat/dir.c |
| * |
| * directory handling functions for fat-based filesystems |
| * |
| * Written 1992,1993 by Werner Almesberger |
| * |
| * Hidden files 1995 by Albert Cahalan <albert@ccs.neu.edu> <adc@coe.neu.edu> |
| * |
| * VFAT extensions by Gordon Chaffee <chaffee@plateau.cs.berkeley.edu> |
| * Merged with msdos fs by Henrik Storner <storner@osiris.ping.dk> |
| * Rewritten for constant inumbers. Plugged buffer overrun in readdir(). AV |
| * Short name translation 1999, 2001 by Wolfram Pienkoss <wp@bszh.de> |
| */ |
| |
| #include <linux/module.h> |
| #include <linux/slab.h> |
| #include <linux/time.h> |
| #include <linux/smp_lock.h> |
| #include <linux/buffer_head.h> |
| #include <linux/compat.h> |
| #include <asm/uaccess.h> |
| #include "fat.h" |
| |
| static inline loff_t fat_make_i_pos(struct super_block *sb, |
| struct buffer_head *bh, |
| struct msdos_dir_entry *de) |
| { |
| return ((loff_t)bh->b_blocknr << MSDOS_SB(sb)->dir_per_block_bits) |
| | (de - (struct msdos_dir_entry *)bh->b_data); |
| } |
| |
| static inline void fat_dir_readahead(struct inode *dir, sector_t iblock, |
| sector_t phys) |
| { |
| struct super_block *sb = dir->i_sb; |
| struct msdos_sb_info *sbi = MSDOS_SB(sb); |
| struct buffer_head *bh; |
| int sec; |
| |
| /* This is not a first sector of cluster, or sec_per_clus == 1 */ |
| if ((iblock & (sbi->sec_per_clus - 1)) || sbi->sec_per_clus == 1) |
| return; |
| /* root dir of FAT12/FAT16 */ |
| if ((sbi->fat_bits != 32) && (dir->i_ino == MSDOS_ROOT_INO)) |
| return; |
| |
| bh = sb_find_get_block(sb, phys); |
| if (bh == NULL || !buffer_uptodate(bh)) { |
| for (sec = 0; sec < sbi->sec_per_clus; sec++) |
| sb_breadahead(sb, phys + sec); |
| } |
| brelse(bh); |
| } |
| |
| /* Returns the inode number of the directory entry at offset pos. If bh is |
| non-NULL, it is brelse'd before. Pos is incremented. The buffer header is |
| returned in bh. |
| AV. Most often we do it item-by-item. Makes sense to optimize. |
| AV. OK, there we go: if both bh and de are non-NULL we assume that we just |
| AV. want the next entry (took one explicit de=NULL in vfat/namei.c). |
| AV. It's done in fat_get_entry() (inlined), here the slow case lives. |
| AV. Additionally, when we return -1 (i.e. reached the end of directory) |
| AV. we make bh NULL. |
| */ |
| static int fat__get_entry(struct inode *dir, loff_t *pos, |
| struct buffer_head **bh, struct msdos_dir_entry **de) |
| { |
| struct super_block *sb = dir->i_sb; |
| sector_t phys, iblock; |
| unsigned long mapped_blocks; |
| int err, offset; |
| |
| next: |
| if (*bh) |
| brelse(*bh); |
| |
| *bh = NULL; |
| iblock = *pos >> sb->s_blocksize_bits; |
| err = fat_bmap(dir, iblock, &phys, &mapped_blocks); |
| if (err || !phys) |
| return -1; /* beyond EOF or error */ |
| |
| fat_dir_readahead(dir, iblock, phys); |
| |
| *bh = sb_bread(sb, phys); |
| if (*bh == NULL) { |
| printk(KERN_ERR "FAT: Directory bread(block %llu) failed\n", |
| (unsigned long long)phys); |
| /* skip this block */ |
| *pos = (iblock + 1) << sb->s_blocksize_bits; |
| goto next; |
| } |
| |
| offset = *pos & (sb->s_blocksize - 1); |
| *pos += sizeof(struct msdos_dir_entry); |
| *de = (struct msdos_dir_entry *)((*bh)->b_data + offset); |
| |
| return 0; |
| } |
| |
| static inline int fat_get_entry(struct inode *dir, loff_t *pos, |
| struct buffer_head **bh, |
| struct msdos_dir_entry **de) |
| { |
| /* Fast stuff first */ |
| if (*bh && *de && |
| (*de - (struct msdos_dir_entry *)(*bh)->b_data) < MSDOS_SB(dir->i_sb)->dir_per_block - 1) { |
| *pos += sizeof(struct msdos_dir_entry); |
| (*de)++; |
| return 0; |
| } |
| return fat__get_entry(dir, pos, bh, de); |
| } |
| |
| /* |
| * Convert Unicode 16 to UTF-8, translated Unicode, or ASCII. |
| * If uni_xlate is enabled and we can't get a 1:1 conversion, use a |
| * colon as an escape character since it is normally invalid on the vfat |
| * filesystem. The following four characters are the hexadecimal digits |
| * of Unicode value. This lets us do a full dump and restore of Unicode |
| * filenames. We could get into some trouble with long Unicode names, |
| * but ignore that right now. |
| * Ahem... Stack smashing in ring 0 isn't fun. Fixed. |
| */ |
| static int uni16_to_x8(unsigned char *ascii, const wchar_t *uni, int len, |
| int uni_xlate, struct nls_table *nls) |
| { |
| const wchar_t *ip; |
| wchar_t ec; |
| unsigned char *op, nc; |
| int charlen; |
| int k; |
| |
| ip = uni; |
| op = ascii; |
| |
| while (*ip && ((len - NLS_MAX_CHARSET_SIZE) > 0)) { |
| ec = *ip++; |
| if ( (charlen = nls->uni2char(ec, op, NLS_MAX_CHARSET_SIZE)) > 0) { |
| op += charlen; |
| len -= charlen; |
| } else { |
| if (uni_xlate == 1) { |
| *op = ':'; |
| for (k = 4; k > 0; k--) { |
| nc = ec & 0xF; |
| op[k] = nc > 9 ? nc + ('a' - 10) |
| : nc + '0'; |
| ec >>= 4; |
| } |
| op += 5; |
| len -= 5; |
| } else { |
| *op++ = '?'; |
| len--; |
| } |
| } |
| } |
| |
| if (unlikely(*ip)) { |
| printk(KERN_WARNING "FAT: filename was truncated while " |
| "converting."); |
| } |
| |
| *op = 0; |
| return (op - ascii); |
| } |
| |
| static inline int fat_uni_to_x8(struct msdos_sb_info *sbi, const wchar_t *uni, |
| unsigned char *buf, int size) |
| { |
| if (sbi->options.utf8) |
| return utf8_wcstombs(buf, uni, size); |
| else |
| return uni16_to_x8(buf, uni, size, sbi->options.unicode_xlate, |
| sbi->nls_io); |
| } |
| |
| static inline int |
| fat_short2uni(struct nls_table *t, unsigned char *c, int clen, wchar_t *uni) |
| { |
| int charlen; |
| |
| charlen = t->char2uni(c, clen, uni); |
| if (charlen < 0) { |
| *uni = 0x003f; /* a question mark */ |
| charlen = 1; |
| } |
| return charlen; |
| } |
| |
| static inline int |
| fat_short2lower_uni(struct nls_table *t, unsigned char *c, int clen, wchar_t *uni) |
| { |
| int charlen; |
| wchar_t wc; |
| |
| charlen = t->char2uni(c, clen, &wc); |
| if (charlen < 0) { |
| *uni = 0x003f; /* a question mark */ |
| charlen = 1; |
| } else if (charlen <= 1) { |
| unsigned char nc = t->charset2lower[*c]; |
| |
| if (!nc) |
| nc = *c; |
| |
| if ( (charlen = t->char2uni(&nc, 1, uni)) < 0) { |
| *uni = 0x003f; /* a question mark */ |
| charlen = 1; |
| } |
| } else |
| *uni = wc; |
| |
| return charlen; |
| } |
| |
| static inline int |
| fat_shortname2uni(struct nls_table *nls, unsigned char *buf, int buf_size, |
| wchar_t *uni_buf, unsigned short opt, int lower) |
| { |
| int len = 0; |
| |
| if (opt & VFAT_SFN_DISPLAY_LOWER) |
| len = fat_short2lower_uni(nls, buf, buf_size, uni_buf); |
| else if (opt & VFAT_SFN_DISPLAY_WIN95) |
| len = fat_short2uni(nls, buf, buf_size, uni_buf); |
| else if (opt & VFAT_SFN_DISPLAY_WINNT) { |
| if (lower) |
| len = fat_short2lower_uni(nls, buf, buf_size, uni_buf); |
| else |
| len = fat_short2uni(nls, buf, buf_size, uni_buf); |
| } else |
| len = fat_short2uni(nls, buf, buf_size, uni_buf); |
| |
| return len; |
| } |
| |
| static inline int fat_name_match(struct msdos_sb_info *sbi, |
| const unsigned char *a, int a_len, |
| const unsigned char *b, int b_len) |
| { |
| if (a_len != b_len) |
| return 0; |
| |
| if (sbi->options.name_check != 's') |
| return !nls_strnicmp(sbi->nls_io, a, b, a_len); |
| else |
| return !memcmp(a, b, a_len); |
| } |
| |
| enum { PARSE_INVALID = 1, PARSE_NOT_LONGNAME, PARSE_EOF, }; |
| |
| /** |
| * fat_parse_long - Parse extended directory entry. |
| * |
| * This function returns zero on success, negative value on error, or one of |
| * the following: |
| * |
| * %PARSE_INVALID - Directory entry is invalid. |
| * %PARSE_NOT_LONGNAME - Directory entry does not contain longname. |
| * %PARSE_EOF - Directory has no more entries. |
| */ |
| static int fat_parse_long(struct inode *dir, loff_t *pos, |
| struct buffer_head **bh, struct msdos_dir_entry **de, |
| wchar_t **unicode, unsigned char *nr_slots) |
| { |
| struct msdos_dir_slot *ds; |
| unsigned char id, slot, slots, alias_checksum; |
| |
| if (!*unicode) { |
| *unicode = __getname(); |
| if (!*unicode) { |
| brelse(*bh); |
| return -ENOMEM; |
| } |
| } |
| parse_long: |
| slots = 0; |
| ds = (struct msdos_dir_slot *)*de; |
| id = ds->id; |
| if (!(id & 0x40)) |
| return PARSE_INVALID; |
| slots = id & ~0x40; |
| if (slots > 20 || !slots) /* ceil(256 * 2 / 26) */ |
| return PARSE_INVALID; |
| *nr_slots = slots; |
| alias_checksum = ds->alias_checksum; |
| |
| slot = slots; |
| while (1) { |
| int offset; |
| |
| slot--; |
| offset = slot * 13; |
| fat16_towchar(*unicode + offset, ds->name0_4, 5); |
| fat16_towchar(*unicode + offset + 5, ds->name5_10, 6); |
| fat16_towchar(*unicode + offset + 11, ds->name11_12, 2); |
| |
| if (ds->id & 0x40) |
| (*unicode)[offset + 13] = 0; |
| if (fat_get_entry(dir, pos, bh, de) < 0) |
| return PARSE_EOF; |
| if (slot == 0) |
| break; |
| ds = (struct msdos_dir_slot *)*de; |
| if (ds->attr != ATTR_EXT) |
| return PARSE_NOT_LONGNAME; |
| if ((ds->id & ~0x40) != slot) |
| goto parse_long; |
| if (ds->alias_checksum != alias_checksum) |
| goto parse_long; |
| } |
| if ((*de)->name[0] == DELETED_FLAG) |
| return PARSE_INVALID; |
| if ((*de)->attr == ATTR_EXT) |
| goto parse_long; |
| if (IS_FREE((*de)->name) || ((*de)->attr & ATTR_VOLUME)) |
| return PARSE_INVALID; |
| if (fat_checksum((*de)->name) != alias_checksum) |
| *nr_slots = 0; |
| |
| return 0; |
| } |
| |
| /* |
| * Maximum buffer size of short name. |
| * [(MSDOS_NAME + '.') * max one char + nul] |
| * For msdos style, ['.' (hidden) + MSDOS_NAME + '.' + nul] |
| */ |
| #define FAT_MAX_SHORT_SIZE ((MSDOS_NAME + 1) * NLS_MAX_CHARSET_SIZE + 1) |
| /* |
| * Maximum buffer size of unicode chars from slots. |
| * [(max longname slots * 13 (size in a slot) + nul) * sizeof(wchar_t)] |
| */ |
| #define FAT_MAX_UNI_CHARS ((MSDOS_SLOTS - 1) * 13 + 1) |
| #define FAT_MAX_UNI_SIZE (FAT_MAX_UNI_CHARS * sizeof(wchar_t)) |
| |
| /* |
| * Return values: negative -> error, 0 -> not found, positive -> found, |
| * value is the total amount of slots, including the shortname entry. |
| */ |
| int fat_search_long(struct inode *inode, const unsigned char *name, |
| int name_len, struct fat_slot_info *sinfo) |
| { |
| struct super_block *sb = inode->i_sb; |
| struct msdos_sb_info *sbi = MSDOS_SB(sb); |
| struct buffer_head *bh = NULL; |
| struct msdos_dir_entry *de; |
| struct nls_table *nls_disk = sbi->nls_disk; |
| unsigned char nr_slots; |
| wchar_t bufuname[14]; |
| wchar_t *unicode = NULL; |
| unsigned char work[MSDOS_NAME]; |
| unsigned char bufname[FAT_MAX_SHORT_SIZE]; |
| unsigned short opt_shortname = sbi->options.shortname; |
| loff_t cpos = 0; |
| int chl, i, j, last_u, err, len; |
| |
| err = -ENOENT; |
| while (1) { |
| if (fat_get_entry(inode, &cpos, &bh, &de) == -1) |
| goto end_of_dir; |
| parse_record: |
| nr_slots = 0; |
| if (de->name[0] == DELETED_FLAG) |
| continue; |
| if (de->attr != ATTR_EXT && (de->attr & ATTR_VOLUME)) |
| continue; |
| if (de->attr != ATTR_EXT && IS_FREE(de->name)) |
| continue; |
| if (de->attr == ATTR_EXT) { |
| int status = fat_parse_long(inode, &cpos, &bh, &de, |
| &unicode, &nr_slots); |
| if (status < 0) |
| return status; |
| else if (status == PARSE_INVALID) |
| continue; |
| else if (status == PARSE_NOT_LONGNAME) |
| goto parse_record; |
| else if (status == PARSE_EOF) |
| goto end_of_dir; |
| } |
| |
| memcpy(work, de->name, sizeof(de->name)); |
| /* see namei.c, msdos_format_name */ |
| if (work[0] == 0x05) |
| work[0] = 0xE5; |
| for (i = 0, j = 0, last_u = 0; i < 8;) { |
| if (!work[i]) |
| break; |
| chl = fat_shortname2uni(nls_disk, &work[i], 8 - i, |
| &bufuname[j++], opt_shortname, |
| de->lcase & CASE_LOWER_BASE); |
| if (chl <= 1) { |
| if (work[i] != ' ') |
| last_u = j; |
| } else { |
| last_u = j; |
| } |
| i += chl; |
| } |
| j = last_u; |
| fat_short2uni(nls_disk, ".", 1, &bufuname[j++]); |
| for (i = 8; i < MSDOS_NAME;) { |
| if (!work[i]) |
| break; |
| chl = fat_shortname2uni(nls_disk, &work[i], |
| MSDOS_NAME - i, |
| &bufuname[j++], opt_shortname, |
| de->lcase & CASE_LOWER_EXT); |
| if (chl <= 1) { |
| if (work[i] != ' ') |
| last_u = j; |
| } else { |
| last_u = j; |
| } |
| i += chl; |
| } |
| if (!last_u) |
| continue; |
| |
| /* Compare shortname */ |
| bufuname[last_u] = 0x0000; |
| len = fat_uni_to_x8(sbi, bufuname, bufname, sizeof(bufname)); |
| if (fat_name_match(sbi, name, name_len, bufname, len)) |
| goto found; |
| |
| if (nr_slots) { |
| void *longname = unicode + FAT_MAX_UNI_CHARS; |
| int size = PATH_MAX - FAT_MAX_UNI_SIZE; |
| |
| /* Compare longname */ |
| len = fat_uni_to_x8(sbi, unicode, longname, size); |
| if (fat_name_match(sbi, name, name_len, longname, len)) |
| goto found; |
| } |
| } |
| |
| found: |
| nr_slots++; /* include the de */ |
| sinfo->slot_off = cpos - nr_slots * sizeof(*de); |
| sinfo->nr_slots = nr_slots; |
| sinfo->de = de; |
| sinfo->bh = bh; |
| sinfo->i_pos = fat_make_i_pos(sb, sinfo->bh, sinfo->de); |
| err = 0; |
| end_of_dir: |
| if (unicode) |
| __putname(unicode); |
| |
| return err; |
| } |
| |
| EXPORT_SYMBOL_GPL(fat_search_long); |
| |
| struct fat_ioctl_filldir_callback { |
| void __user *dirent; |
| int result; |
| /* for dir ioctl */ |
| const char *longname; |
| int long_len; |
| const char *shortname; |
| int short_len; |
| }; |
| |
| static int __fat_readdir(struct inode *inode, struct file *filp, void *dirent, |
| filldir_t filldir, int short_only, int both) |
| { |
| struct super_block *sb = inode->i_sb; |
| struct msdos_sb_info *sbi = MSDOS_SB(sb); |
| struct buffer_head *bh; |
| struct msdos_dir_entry *de; |
| struct nls_table *nls_disk = sbi->nls_disk; |
| unsigned char nr_slots; |
| wchar_t bufuname[14]; |
| wchar_t *unicode = NULL; |
| unsigned char c, work[MSDOS_NAME]; |
| unsigned char bufname[FAT_MAX_SHORT_SIZE], *ptname = bufname; |
| unsigned short opt_shortname = sbi->options.shortname; |
| int isvfat = sbi->options.isvfat; |
| int nocase = sbi->options.nocase; |
| const char *fill_name = NULL; |
| unsigned long inum; |
| unsigned long lpos, dummy, *furrfu = &lpos; |
| loff_t cpos; |
| int chi, chl, i, i2, j, last, last_u, dotoffset = 0, fill_len = 0; |
| int ret = 0; |
| |
| lock_super(sb); |
| |
| cpos = filp->f_pos; |
| /* Fake . and .. for the root directory. */ |
| if (inode->i_ino == MSDOS_ROOT_INO) { |
| while (cpos < 2) { |
| if (filldir(dirent, "..", cpos+1, cpos, MSDOS_ROOT_INO, DT_DIR) < 0) |
| goto out; |
| cpos++; |
| filp->f_pos++; |
| } |
| if (cpos == 2) { |
| dummy = 2; |
| furrfu = &dummy; |
| cpos = 0; |
| } |
| } |
| if (cpos & (sizeof(struct msdos_dir_entry) - 1)) { |
| ret = -ENOENT; |
| goto out; |
| } |
| |
| bh = NULL; |
| get_new: |
| if (fat_get_entry(inode, &cpos, &bh, &de) == -1) |
| goto end_of_dir; |
| parse_record: |
| nr_slots = 0; |
| /* |
| * Check for long filename entry, but if short_only, we don't |
| * need to parse long filename. |
| */ |
| if (isvfat && !short_only) { |
| if (de->name[0] == DELETED_FLAG) |
| goto record_end; |
| if (de->attr != ATTR_EXT && (de->attr & ATTR_VOLUME)) |
| goto record_end; |
| if (de->attr != ATTR_EXT && IS_FREE(de->name)) |
| goto record_end; |
| } else { |
| if ((de->attr & ATTR_VOLUME) || IS_FREE(de->name)) |
| goto record_end; |
| } |
| |
| if (isvfat && de->attr == ATTR_EXT) { |
| int status = fat_parse_long(inode, &cpos, &bh, &de, |
| &unicode, &nr_slots); |
| if (status < 0) { |
| filp->f_pos = cpos; |
| ret = status; |
| goto out; |
| } else if (status == PARSE_INVALID) |
| goto record_end; |
| else if (status == PARSE_NOT_LONGNAME) |
| goto parse_record; |
| else if (status == PARSE_EOF) |
| goto end_of_dir; |
| |
| if (nr_slots) { |
| void *longname = unicode + FAT_MAX_UNI_CHARS; |
| int size = PATH_MAX - FAT_MAX_UNI_SIZE; |
| int len = fat_uni_to_x8(sbi, unicode, longname, size); |
| |
| fill_name = longname; |
| fill_len = len; |
| /* !both && !short_only, so we don't need shortname. */ |
| if (!both) |
| goto start_filldir; |
| } |
| } |
| |
| if (sbi->options.dotsOK) { |
| ptname = bufname; |
| dotoffset = 0; |
| if (de->attr & ATTR_HIDDEN) { |
| *ptname++ = '.'; |
| dotoffset = 1; |
| } |
| } |
| |
| memcpy(work, de->name, sizeof(de->name)); |
| /* see namei.c, msdos_format_name */ |
| if (work[0] == 0x05) |
| work[0] = 0xE5; |
| for (i = 0, j = 0, last = 0, last_u = 0; i < 8;) { |
| if (!(c = work[i])) |
| break; |
| chl = fat_shortname2uni(nls_disk, &work[i], 8 - i, |
| &bufuname[j++], opt_shortname, |
| de->lcase & CASE_LOWER_BASE); |
| if (chl <= 1) { |
| ptname[i++] = (!nocase && c>='A' && c<='Z') ? c+32 : c; |
| if (c != ' ') { |
| last = i; |
| last_u = j; |
| } |
| } else { |
| last_u = j; |
| for (chi = 0; chi < chl && i < 8; chi++) { |
| ptname[i] = work[i]; |
| i++; last = i; |
| } |
| } |
| } |
| i = last; |
| j = last_u; |
| fat_short2uni(nls_disk, ".", 1, &bufuname[j++]); |
| ptname[i++] = '.'; |
| for (i2 = 8; i2 < MSDOS_NAME;) { |
| if (!(c = work[i2])) |
| break; |
| chl = fat_shortname2uni(nls_disk, &work[i2], MSDOS_NAME - i2, |
| &bufuname[j++], opt_shortname, |
| de->lcase & CASE_LOWER_EXT); |
| if (chl <= 1) { |
| i2++; |
| ptname[i++] = (!nocase && c>='A' && c<='Z') ? c+32 : c; |
| if (c != ' ') { |
| last = i; |
| last_u = j; |
| } |
| } else { |
| last_u = j; |
| for (chi = 0; chi < chl && i2 < MSDOS_NAME; chi++) { |
| ptname[i++] = work[i2++]; |
| last = i; |
| } |
| } |
| } |
| if (!last) |
| goto record_end; |
| |
| i = last + dotoffset; |
| j = last_u; |
| |
| if (isvfat) { |
| bufuname[j] = 0x0000; |
| i = fat_uni_to_x8(sbi, bufuname, bufname, sizeof(bufname)); |
| } |
| if (nr_slots) { |
| /* hack for fat_ioctl_filldir() */ |
| struct fat_ioctl_filldir_callback *p = dirent; |
| |
| p->longname = fill_name; |
| p->long_len = fill_len; |
| p->shortname = bufname; |
| p->short_len = i; |
| fill_name = NULL; |
| fill_len = 0; |
| } else { |
| fill_name = bufname; |
| fill_len = i; |
| } |
| |
| start_filldir: |
| lpos = cpos - (nr_slots + 1) * sizeof(struct msdos_dir_entry); |
| if (!memcmp(de->name, MSDOS_DOT, MSDOS_NAME)) |
| inum = inode->i_ino; |
| else if (!memcmp(de->name, MSDOS_DOTDOT, MSDOS_NAME)) { |
| inum = parent_ino(filp->f_path.dentry); |
| } else { |
| loff_t i_pos = fat_make_i_pos(sb, bh, de); |
| struct inode *tmp = fat_iget(sb, i_pos); |
| if (tmp) { |
| inum = tmp->i_ino; |
| iput(tmp); |
| } else |
| inum = iunique(sb, MSDOS_ROOT_INO); |
| } |
| |
| if (filldir(dirent, fill_name, fill_len, *furrfu, inum, |
| (de->attr & ATTR_DIR) ? DT_DIR : DT_REG) < 0) |
| goto fill_failed; |
| |
| record_end: |
| furrfu = &lpos; |
| filp->f_pos = cpos; |
| goto get_new; |
| end_of_dir: |
| filp->f_pos = cpos; |
| fill_failed: |
| brelse(bh); |
| if (unicode) |
| __putname(unicode); |
| out: |
| unlock_super(sb); |
| return ret; |
| } |
| |
| static int fat_readdir(struct file *filp, void *dirent, filldir_t filldir) |
| { |
| struct inode *inode = filp->f_path.dentry->d_inode; |
| return __fat_readdir(inode, filp, dirent, filldir, 0, 0); |
| } |
| |
| #define FAT_IOCTL_FILLDIR_FUNC(func, dirent_type) \ |
| static int func(void *__buf, const char *name, int name_len, \ |
| loff_t offset, u64 ino, unsigned int d_type) \ |
| { \ |
| struct fat_ioctl_filldir_callback *buf = __buf; \ |
| struct dirent_type __user *d1 = buf->dirent; \ |
| struct dirent_type __user *d2 = d1 + 1; \ |
| \ |
| if (buf->result) \ |
| return -EINVAL; \ |
| buf->result++; \ |
| \ |
| if (name != NULL) { \ |
| /* dirent has only short name */ \ |
| if (name_len >= sizeof(d1->d_name)) \ |
| name_len = sizeof(d1->d_name) - 1; \ |
| \ |
| if (put_user(0, d2->d_name) || \ |
| put_user(0, &d2->d_reclen) || \ |
| copy_to_user(d1->d_name, name, name_len) || \ |
| put_user(0, d1->d_name + name_len) || \ |
| put_user(name_len, &d1->d_reclen)) \ |
| goto efault; \ |
| } else { \ |
| /* dirent has short and long name */ \ |
| const char *longname = buf->longname; \ |
| int long_len = buf->long_len; \ |
| const char *shortname = buf->shortname; \ |
| int short_len = buf->short_len; \ |
| \ |
| if (long_len >= sizeof(d1->d_name)) \ |
| long_len = sizeof(d1->d_name) - 1; \ |
| if (short_len >= sizeof(d1->d_name)) \ |
| short_len = sizeof(d1->d_name) - 1; \ |
| \ |
| if (copy_to_user(d2->d_name, longname, long_len) || \ |
| put_user(0, d2->d_name + long_len) || \ |
| put_user(long_len, &d2->d_reclen) || \ |
| put_user(ino, &d2->d_ino) || \ |
| put_user(offset, &d2->d_off) || \ |
| copy_to_user(d1->d_name, shortname, short_len) || \ |
| put_user(0, d1->d_name + short_len) || \ |
| put_user(short_len, &d1->d_reclen)) \ |
| goto efault; \ |
| } \ |
| return 0; \ |
| efault: \ |
| buf->result = -EFAULT; \ |
| return -EFAULT; \ |
| } |
| |
| FAT_IOCTL_FILLDIR_FUNC(fat_ioctl_filldir, __fat_dirent) |
| |
| static int fat_ioctl_readdir(struct inode *inode, struct file *filp, |
| void __user *dirent, filldir_t filldir, |
| int short_only, int both) |
| { |
| struct fat_ioctl_filldir_callback buf; |
| int ret; |
| |
| buf.dirent = dirent; |
| buf.result = 0; |
| mutex_lock(&inode->i_mutex); |
| ret = -ENOENT; |
| if (!IS_DEADDIR(inode)) { |
| ret = __fat_readdir(inode, filp, &buf, filldir, |
| short_only, both); |
| } |
| mutex_unlock(&inode->i_mutex); |
| if (ret >= 0) |
| ret = buf.result; |
| return ret; |
| } |
| |
| static int fat_dir_ioctl(struct inode *inode, struct file *filp, |
| unsigned int cmd, unsigned long arg) |
| { |
| struct __fat_dirent __user *d1 = (struct __fat_dirent __user *)arg; |
| int short_only, both; |
| |
| switch (cmd) { |
| case VFAT_IOCTL_READDIR_SHORT: |
| short_only = 1; |
| both = 0; |
| break; |
| case VFAT_IOCTL_READDIR_BOTH: |
| short_only = 0; |
| both = 1; |
| break; |
| default: |
| return fat_generic_ioctl(inode, filp, cmd, arg); |
| } |
| |
| if (!access_ok(VERIFY_WRITE, d1, sizeof(struct __fat_dirent[2]))) |
| return -EFAULT; |
| /* |
| * Yes, we don't need this put_user() absolutely. However old |
| * code didn't return the right value. So, app use this value, |
| * in order to check whether it is EOF. |
| */ |
| if (put_user(0, &d1->d_reclen)) |
| return -EFAULT; |
| |
| return fat_ioctl_readdir(inode, filp, d1, fat_ioctl_filldir, |
| short_only, both); |
| } |
| |
| #ifdef CONFIG_COMPAT |
| #define VFAT_IOCTL_READDIR_BOTH32 _IOR('r', 1, struct compat_dirent[2]) |
| #define VFAT_IOCTL_READDIR_SHORT32 _IOR('r', 2, struct compat_dirent[2]) |
| |
| FAT_IOCTL_FILLDIR_FUNC(fat_compat_ioctl_filldir, compat_dirent) |
| |
| static long fat_compat_dir_ioctl(struct file *filp, unsigned cmd, |
| unsigned long arg) |
| { |
| struct inode *inode = filp->f_path.dentry->d_inode; |
| struct compat_dirent __user *d1 = compat_ptr(arg); |
| int short_only, both; |
| |
| switch (cmd) { |
| case VFAT_IOCTL_READDIR_SHORT32: |
| short_only = 1; |
| both = 0; |
| break; |
| case VFAT_IOCTL_READDIR_BOTH32: |
| short_only = 0; |
| both = 1; |
| break; |
| default: |
| return -ENOIOCTLCMD; |
| } |
| |
| if (!access_ok(VERIFY_WRITE, d1, sizeof(struct compat_dirent[2]))) |
| return -EFAULT; |
| /* |
| * Yes, we don't need this put_user() absolutely. However old |
| * code didn't return the right value. So, app use this value, |
| * in order to check whether it is EOF. |
| */ |
| if (put_user(0, &d1->d_reclen)) |
| return -EFAULT; |
| |
| return fat_ioctl_readdir(inode, filp, d1, fat_compat_ioctl_filldir, |
| short_only, both); |
| } |
| #endif /* CONFIG_COMPAT */ |
| |
| const struct file_operations fat_dir_operations = { |
| .read = generic_read_dir, |
| .readdir = fat_readdir, |
| .ioctl = fat_dir_ioctl, |
| #ifdef CONFIG_COMPAT |
| .compat_ioctl = fat_compat_dir_ioctl, |
| #endif |
| .fsync = file_fsync, |
| .llseek = generic_file_llseek, |
| }; |
| |
| static int fat_get_short_entry(struct inode *dir, loff_t *pos, |
| struct buffer_head **bh, |
| struct msdos_dir_entry **de) |
| { |
| while (fat_get_entry(dir, pos, bh, de) >= 0) { |
| /* free entry or long name entry or volume label */ |
| if (!IS_FREE((*de)->name) && !((*de)->attr & ATTR_VOLUME)) |
| return 0; |
| } |
| return -ENOENT; |
| } |
| |
| /* |
| * The ".." entry can not provide the "struct fat_slot_info" informations |
| * for inode. So, this function provide the some informations only. |
| */ |
| int fat_get_dotdot_entry(struct inode *dir, struct buffer_head **bh, |
| struct msdos_dir_entry **de, loff_t *i_pos) |
| { |
| loff_t offset; |
| |
| offset = 0; |
| *bh = NULL; |
| while (fat_get_short_entry(dir, &offset, bh, de) >= 0) { |
| if (!strncmp((*de)->name, MSDOS_DOTDOT, MSDOS_NAME)) { |
| *i_pos = fat_make_i_pos(dir->i_sb, *bh, *de); |
| return 0; |
| } |
| } |
| return -ENOENT; |
| } |
| |
| EXPORT_SYMBOL_GPL(fat_get_dotdot_entry); |
| |
| /* See if directory is empty */ |
| int fat_dir_empty(struct inode *dir) |
| { |
| struct buffer_head *bh; |
| struct msdos_dir_entry *de; |
| loff_t cpos; |
| int result = 0; |
| |
| bh = NULL; |
| cpos = 0; |
| while (fat_get_short_entry(dir, &cpos, &bh, &de) >= 0) { |
| if (strncmp(de->name, MSDOS_DOT , MSDOS_NAME) && |
| strncmp(de->name, MSDOS_DOTDOT, MSDOS_NAME)) { |
| result = -ENOTEMPTY; |
| break; |
| } |
| } |
| brelse(bh); |
| return result; |
| } |
| |
| EXPORT_SYMBOL_GPL(fat_dir_empty); |
| |
| /* |
| * fat_subdirs counts the number of sub-directories of dir. It can be run |
| * on directories being created. |
| */ |
| int fat_subdirs(struct inode *dir) |
| { |
| struct buffer_head *bh; |
| struct msdos_dir_entry *de; |
| loff_t cpos; |
| int count = 0; |
| |
| bh = NULL; |
| cpos = 0; |
| while (fat_get_short_entry(dir, &cpos, &bh, &de) >= 0) { |
| if (de->attr & ATTR_DIR) |
| count++; |
| } |
| brelse(bh); |
| return count; |
| } |
| |
| /* |
| * Scans a directory for a given file (name points to its formatted name). |
| * Returns an error code or zero. |
| */ |
| int fat_scan(struct inode *dir, const unsigned char *name, |
| struct fat_slot_info *sinfo) |
| { |
| struct super_block *sb = dir->i_sb; |
| |
| sinfo->slot_off = 0; |
| sinfo->bh = NULL; |
| while (fat_get_short_entry(dir, &sinfo->slot_off, &sinfo->bh, |
| &sinfo->de) >= 0) { |
| if (!strncmp(sinfo->de->name, name, MSDOS_NAME)) { |
| sinfo->slot_off -= sizeof(*sinfo->de); |
| sinfo->nr_slots = 1; |
| sinfo->i_pos = fat_make_i_pos(sb, sinfo->bh, sinfo->de); |
| return 0; |
| } |
| } |
| return -ENOENT; |
| } |
| |
| EXPORT_SYMBOL_GPL(fat_scan); |
| |
| static int __fat_remove_entries(struct inode *dir, loff_t pos, int nr_slots) |
| { |
| struct super_block *sb = dir->i_sb; |
| struct buffer_head *bh; |
| struct msdos_dir_entry *de, *endp; |
| int err = 0, orig_slots; |
| |
| while (nr_slots) { |
| bh = NULL; |
| if (fat_get_entry(dir, &pos, &bh, &de) < 0) { |
| err = -EIO; |
| break; |
| } |
| |
| orig_slots = nr_slots; |
| endp = (struct msdos_dir_entry *)(bh->b_data + sb->s_blocksize); |
| while (nr_slots && de < endp) { |
| de->name[0] = DELETED_FLAG; |
| de++; |
| nr_slots--; |
| } |
| mark_buffer_dirty(bh); |
| if (IS_DIRSYNC(dir)) |
| err = sync_dirty_buffer(bh); |
| brelse(bh); |
| if (err) |
| break; |
| |
| /* pos is *next* de's position, so this does `- sizeof(de)' */ |
| pos += ((orig_slots - nr_slots) * sizeof(*de)) - sizeof(*de); |
| } |
| |
| return err; |
| } |
| |
| int fat_remove_entries(struct inode *dir, struct fat_slot_info *sinfo) |
| { |
| struct msdos_dir_entry *de; |
| struct buffer_head *bh; |
| int err = 0, nr_slots; |
| |
| /* |
| * First stage: Remove the shortname. By this, the directory |
| * entry is removed. |
| */ |
| nr_slots = sinfo->nr_slots; |
| de = sinfo->de; |
| sinfo->de = NULL; |
| bh = sinfo->bh; |
| sinfo->bh = NULL; |
| while (nr_slots && de >= (struct msdos_dir_entry *)bh->b_data) { |
| de->name[0] = DELETED_FLAG; |
| de--; |
| nr_slots--; |
| } |
| mark_buffer_dirty(bh); |
| if (IS_DIRSYNC(dir)) |
| err = sync_dirty_buffer(bh); |
| brelse(bh); |
| if (err) |
| return err; |
| dir->i_version++; |
| |
| if (nr_slots) { |
| /* |
| * Second stage: remove the remaining longname slots. |
| * (This directory entry is already removed, and so return |
| * the success) |
| */ |
| err = __fat_remove_entries(dir, sinfo->slot_off, nr_slots); |
| if (err) { |
| printk(KERN_WARNING |
| "FAT: Couldn't remove the long name slots\n"); |
| } |
| } |
| |
| dir->i_mtime = dir->i_atime = CURRENT_TIME_SEC; |
| if (IS_DIRSYNC(dir)) |
| (void)fat_sync_inode(dir); |
| else |
| mark_inode_dirty(dir); |
| |
| return 0; |
| } |
| |
| EXPORT_SYMBOL_GPL(fat_remove_entries); |
| |
| static int fat_zeroed_cluster(struct inode *dir, sector_t blknr, int nr_used, |
| struct buffer_head **bhs, int nr_bhs) |
| { |
| struct super_block *sb = dir->i_sb; |
| sector_t last_blknr = blknr + MSDOS_SB(sb)->sec_per_clus; |
| int err, i, n; |
| |
| /* Zeroing the unused blocks on this cluster */ |
| blknr += nr_used; |
| n = nr_used; |
| while (blknr < last_blknr) { |
| bhs[n] = sb_getblk(sb, blknr); |
| if (!bhs[n]) { |
| err = -ENOMEM; |
| goto error; |
| } |
| memset(bhs[n]->b_data, 0, sb->s_blocksize); |
| set_buffer_uptodate(bhs[n]); |
| mark_buffer_dirty(bhs[n]); |
| |
| n++; |
| blknr++; |
| if (n == nr_bhs) { |
| if (IS_DIRSYNC(dir)) { |
| err = fat_sync_bhs(bhs, n); |
| if (err) |
| goto error; |
| } |
| for (i = 0; i < n; i++) |
| brelse(bhs[i]); |
| n = 0; |
| } |
| } |
| if (IS_DIRSYNC(dir)) { |
| err = fat_sync_bhs(bhs, n); |
| if (err) |
| goto error; |
| } |
| for (i = 0; i < n; i++) |
| brelse(bhs[i]); |
| |
| return 0; |
| |
| error: |
| for (i = 0; i < n; i++) |
| bforget(bhs[i]); |
| return err; |
| } |
| |
| int fat_alloc_new_dir(struct inode *dir, struct timespec *ts) |
| { |
| struct super_block *sb = dir->i_sb; |
| struct msdos_sb_info *sbi = MSDOS_SB(sb); |
| struct buffer_head *bhs[MAX_BUF_PER_PAGE]; |
| struct msdos_dir_entry *de; |
| sector_t blknr; |
| __le16 date, time; |
| int err, cluster; |
| |
| err = fat_alloc_clusters(dir, &cluster, 1); |
| if (err) |
| goto error; |
| |
| blknr = fat_clus_to_blknr(sbi, cluster); |
| bhs[0] = sb_getblk(sb, blknr); |
| if (!bhs[0]) { |
| err = -ENOMEM; |
| goto error_free; |
| } |
| |
| fat_date_unix2dos(ts->tv_sec, &time, &date, sbi->options.tz_utc); |
| |
| de = (struct msdos_dir_entry *)bhs[0]->b_data; |
| /* filling the new directory slots ("." and ".." entries) */ |
| memcpy(de[0].name, MSDOS_DOT, MSDOS_NAME); |
| memcpy(de[1].name, MSDOS_DOTDOT, MSDOS_NAME); |
| de->attr = de[1].attr = ATTR_DIR; |
| de[0].lcase = de[1].lcase = 0; |
| de[0].time = de[1].time = time; |
| de[0].date = de[1].date = date; |
| de[0].ctime_cs = de[1].ctime_cs = 0; |
| if (sbi->options.isvfat) { |
| /* extra timestamps */ |
| de[0].ctime = de[1].ctime = time; |
| de[0].adate = de[0].cdate = de[1].adate = de[1].cdate = date; |
| } else { |
| de[0].ctime = de[1].ctime = 0; |
| de[0].adate = de[0].cdate = de[1].adate = de[1].cdate = 0; |
| } |
| de[0].start = cpu_to_le16(cluster); |
| de[0].starthi = cpu_to_le16(cluster >> 16); |
| de[1].start = cpu_to_le16(MSDOS_I(dir)->i_logstart); |
| de[1].starthi = cpu_to_le16(MSDOS_I(dir)->i_logstart >> 16); |
| de[0].size = de[1].size = 0; |
| memset(de + 2, 0, sb->s_blocksize - 2 * sizeof(*de)); |
| set_buffer_uptodate(bhs[0]); |
| mark_buffer_dirty(bhs[0]); |
| |
| err = fat_zeroed_cluster(dir, blknr, 1, bhs, MAX_BUF_PER_PAGE); |
| if (err) |
| goto error_free; |
| |
| return cluster; |
| |
| error_free: |
| fat_free_clusters(dir, cluster); |
| error: |
| return err; |
| } |
| |
| EXPORT_SYMBOL_GPL(fat_alloc_new_dir); |
| |
| static int fat_add_new_entries(struct inode *dir, void *slots, int nr_slots, |
| int *nr_cluster, struct msdos_dir_entry **de, |
| struct buffer_head **bh, loff_t *i_pos) |
| { |
| struct super_block *sb = dir->i_sb; |
| struct msdos_sb_info *sbi = MSDOS_SB(sb); |
| struct buffer_head *bhs[MAX_BUF_PER_PAGE]; |
| sector_t blknr, start_blknr, last_blknr; |
| unsigned long size, copy; |
| int err, i, n, offset, cluster[2]; |
| |
| /* |
| * The minimum cluster size is 512bytes, and maximum entry |
| * size is 32*slots (672bytes). So, iff the cluster size is |
| * 512bytes, we may need two clusters. |
| */ |
| size = nr_slots * sizeof(struct msdos_dir_entry); |
| *nr_cluster = (size + (sbi->cluster_size - 1)) >> sbi->cluster_bits; |
| BUG_ON(*nr_cluster > 2); |
| |
| err = fat_alloc_clusters(dir, cluster, *nr_cluster); |
| if (err) |
| goto error; |
| |
| /* |
| * First stage: Fill the directory entry. NOTE: This cluster |
| * is not referenced from any inode yet, so updates order is |
| * not important. |
| */ |
| i = n = copy = 0; |
| do { |
| start_blknr = blknr = fat_clus_to_blknr(sbi, cluster[i]); |
| last_blknr = start_blknr + sbi->sec_per_clus; |
| while (blknr < last_blknr) { |
| bhs[n] = sb_getblk(sb, blknr); |
| if (!bhs[n]) { |
| err = -ENOMEM; |
| goto error_nomem; |
| } |
| |
| /* fill the directory entry */ |
| copy = min(size, sb->s_blocksize); |
| memcpy(bhs[n]->b_data, slots, copy); |
| slots += copy; |
| size -= copy; |
| set_buffer_uptodate(bhs[n]); |
| mark_buffer_dirty(bhs[n]); |
| if (!size) |
| break; |
| n++; |
| blknr++; |
| } |
| } while (++i < *nr_cluster); |
| |
| memset(bhs[n]->b_data + copy, 0, sb->s_blocksize - copy); |
| offset = copy - sizeof(struct msdos_dir_entry); |
| get_bh(bhs[n]); |
| *bh = bhs[n]; |
| *de = (struct msdos_dir_entry *)((*bh)->b_data + offset); |
| *i_pos = fat_make_i_pos(sb, *bh, *de); |
| |
| /* Second stage: clear the rest of cluster, and write outs */ |
| err = fat_zeroed_cluster(dir, start_blknr, ++n, bhs, MAX_BUF_PER_PAGE); |
| if (err) |
| goto error_free; |
| |
| return cluster[0]; |
| |
| error_free: |
| brelse(*bh); |
| *bh = NULL; |
| n = 0; |
| error_nomem: |
| for (i = 0; i < n; i++) |
| bforget(bhs[i]); |
| fat_free_clusters(dir, cluster[0]); |
| error: |
| return err; |
| } |
| |
| int fat_add_entries(struct inode *dir, void *slots, int nr_slots, |
| struct fat_slot_info *sinfo) |
| { |
| struct super_block *sb = dir->i_sb; |
| struct msdos_sb_info *sbi = MSDOS_SB(sb); |
| struct buffer_head *bh, *prev, *bhs[3]; /* 32*slots (672bytes) */ |
| struct msdos_dir_entry *de; |
| int err, free_slots, i, nr_bhs; |
| loff_t pos, i_pos; |
| |
| sinfo->nr_slots = nr_slots; |
| |
| /* First stage: search free direcotry entries */ |
| free_slots = nr_bhs = 0; |
| bh = prev = NULL; |
| pos = 0; |
| err = -ENOSPC; |
| while (fat_get_entry(dir, &pos, &bh, &de) > -1) { |
| /* check the maximum size of directory */ |
| if (pos >= FAT_MAX_DIR_SIZE) |
| goto error; |
| |
| if (IS_FREE(de->name)) { |
| if (prev != bh) { |
| get_bh(bh); |
| bhs[nr_bhs] = prev = bh; |
| nr_bhs++; |
| } |
| free_slots++; |
| if (free_slots == nr_slots) |
| goto found; |
| } else { |
| for (i = 0; i < nr_bhs; i++) |
| brelse(bhs[i]); |
| prev = NULL; |
| free_slots = nr_bhs = 0; |
| } |
| } |
| if (dir->i_ino == MSDOS_ROOT_INO) { |
| if (sbi->fat_bits != 32) |
| goto error; |
| } else if (MSDOS_I(dir)->i_start == 0) { |
| printk(KERN_ERR "FAT: Corrupted directory (i_pos %lld)\n", |
| MSDOS_I(dir)->i_pos); |
| err = -EIO; |
| goto error; |
| } |
| |
| found: |
| err = 0; |
| pos -= free_slots * sizeof(*de); |
| nr_slots -= free_slots; |
| if (free_slots) { |
| /* |
| * Second stage: filling the free entries with new entries. |
| * NOTE: If this slots has shortname, first, we write |
| * the long name slots, then write the short name. |
| */ |
| int size = free_slots * sizeof(*de); |
| int offset = pos & (sb->s_blocksize - 1); |
| int long_bhs = nr_bhs - (nr_slots == 0); |
| |
| /* Fill the long name slots. */ |
| for (i = 0; i < long_bhs; i++) { |
| int copy = min_t(int, sb->s_blocksize - offset, size); |
| memcpy(bhs[i]->b_data + offset, slots, copy); |
| mark_buffer_dirty(bhs[i]); |
| offset = 0; |
| slots += copy; |
| size -= copy; |
| } |
| if (long_bhs && IS_DIRSYNC(dir)) |
| err = fat_sync_bhs(bhs, long_bhs); |
| if (!err && i < nr_bhs) { |
| /* Fill the short name slot. */ |
| int copy = min_t(int, sb->s_blocksize - offset, size); |
| memcpy(bhs[i]->b_data + offset, slots, copy); |
| mark_buffer_dirty(bhs[i]); |
| if (IS_DIRSYNC(dir)) |
| err = sync_dirty_buffer(bhs[i]); |
| } |
| for (i = 0; i < nr_bhs; i++) |
| brelse(bhs[i]); |
| if (err) |
| goto error_remove; |
| } |
| |
| if (nr_slots) { |
| int cluster, nr_cluster; |
| |
| /* |
| * Third stage: allocate the cluster for new entries. |
| * And initialize the cluster with new entries, then |
| * add the cluster to dir. |
| */ |
| cluster = fat_add_new_entries(dir, slots, nr_slots, &nr_cluster, |
| &de, &bh, &i_pos); |
| if (cluster < 0) { |
| err = cluster; |
| goto error_remove; |
| } |
| err = fat_chain_add(dir, cluster, nr_cluster); |
| if (err) { |
| fat_free_clusters(dir, cluster); |
| goto error_remove; |
| } |
| if (dir->i_size & (sbi->cluster_size - 1)) { |
| fat_fs_panic(sb, "Odd directory size"); |
| dir->i_size = (dir->i_size + sbi->cluster_size - 1) |
| & ~((loff_t)sbi->cluster_size - 1); |
| } |
| dir->i_size += nr_cluster << sbi->cluster_bits; |
| MSDOS_I(dir)->mmu_private += nr_cluster << sbi->cluster_bits; |
| } |
| sinfo->slot_off = pos; |
| sinfo->de = de; |
| sinfo->bh = bh; |
| sinfo->i_pos = fat_make_i_pos(sb, sinfo->bh, sinfo->de); |
| |
| return 0; |
| |
| error: |
| brelse(bh); |
| for (i = 0; i < nr_bhs; i++) |
| brelse(bhs[i]); |
| return err; |
| |
| error_remove: |
| brelse(bh); |
| if (free_slots) |
| __fat_remove_entries(dir, pos, free_slots); |
| return err; |
| } |
| |
| EXPORT_SYMBOL_GPL(fat_add_entries); |